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What is best Watchdog method, WDOG timer or RTC interrupt?

Question asked by Bora on May 31, 2010
Latest reply on Jul 24, 2011 by PrasanthR



Although there is a dedicated watchdog timer in BF,  since RTC has a separate logic power, I a feeling that using RTC  interrupt may be more reliable than using dedicated watchdog timer.


What is the most reliable method as  watchdog functionality for BF531/532/533?


Best regards,



(From  HW manual)

RTC Programming Model


The primary Real-Time Clock functionality, shown in Figure 16-1  on page 16-3, consists of registers and counters that are powered by an  inde-pendent RTC Vdd supply. This logic is never reset; it comes up in an unknown state when RTC Vdd is first powered on.


RTC_SWCNT Register


This allows the stopwatch o be used as a watchdog timer with a   precision of one second. Writing the running stopwatch to 0 forces it to   stop and interrupt early.